Photocatalytic properties of nano-structured carbon nitride: a comparison with bulk graphitic carbon nitride

We have synthesised two kinds of graphitic carbon nitride (g-C3N4) through a pyrolysis process involving urea and melamine. The obtained products were characterised by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, UV-vis diffuse reflection spectroscopy, and nitrogen adsorption-desorption. The product derived from the urea shows a mesoporous honeycomb-like nanosheet structure (denoted by h-g-C3N4): compared with the bulk product obtained from melamine (denoted by b-g-C3N4), the h-gC(3)N(4) showed better adsorption and higher photo-activity for rhodamine B (RhB) reduction. The h-g-C3N4 also shows good reusability after cyclic adsorption-regeneration. The present results evinced an efficient design, an eco-friendly and convenient photocatalyst, and a tunable photo-reactivity for use in sustainable light-to-energy conversion.